The present disclosure is related to the field of image reconstruction and display. More specifically, the present disclosure is related to rendering and displaying images from digital x-ray tomosynthesis or tomography.
Tomography refers to imaging by sections or sectioning an object into multiple images, and reconstructing the images to view an object of interest. In digital tomosynthesis, one or more x-ray sources and one or more one-dimensional or two-dimensional (2D) x-ray digital detectors are used to acquire a set of projection radiographs of the object. One advantage of tomosynthesis is that it removes the overlapping tissue that can obscure clinical indications or cause false positives. In digital breast tomosynthesis, clinical studies have shown that tomosynthesis is more sensitive and specific than mammography.
During diagnostic review of medical images, the clinician examines the images for abnormalities, fractures, indications of cancer, and other related observable occurrences. The clinician may request additional images to be taken at different angles to better view suspicious areas. In the case of lesions (e.g., masses, distortions and calcifications), the shape or morphology determines the likelihood of the lesion being benign or malignant. In the case of a fracture, the type and location of the fracture will determine the treatment.
Tomosynthesis, as a 3D imaging modality, inherently has the geometric information necessary to reconstruct images at various angles and planes. Instead of acquiring new images, additional images can be reconstructed at different angles using existing tomosynthesis projection data, thereby reducing radiation exposure to the patient. Advanced 3D volume reconstructions that improve the display of the anatomy and, thus the clinician's diagnostic assessment, are also possible in tomosynthesis. However, the conventional method for displaying and viewing tomosynthesis images is to reconstruct a stack of image slices at fixed increments (e.g. 1 mm for tomosynthesis to 3 mm for CT) parallel to the detector which are then reviewed at a later time. This method limits further interrogation and more detailed assessment of the image data.
A method of dynamic reconstruction and rendering of three-dimensional (3D) tomographic images is discussed in U.S. Pat. No. 8,233,690, the content of which is hereby incorporated by reference in its entirety. U.S. Pat. No. 8,233,690 teaches a method of image reconstruction referred to as dynamic reconstruction and rendering (DRR). In DRR, a single image is reconstructed from the projection data in real-time and on-demand. An image can be reconstructed for a region of interest, at any depth and with any reconstruction and processing parameters. The DRR method uses a fast, back-projection filtering method that supports the ability to provide enhanced display and viewing capabilities in tomosynthesis. However, any fast 3D image reconstruction method (i.e. a back projection or iterative method) that is responsive to the user can be used. The reconstruction method can be implemented on a CPU, GPU, FPGAs or any other graphical device.
This document describes methods, systems and components that expand upon the previous DRR methods as disclosed in U.S. Pat. No. 8,233,690.